GN: Do not pass /safeseh to ml64.exe

build/config/win/BUILD.gn

Index: build/config/win/BUILD.gn
diff --git a/build/config/win/BUILD.gn b/build/config/win/BUILD.gn
index dec7a5abfb42305d2e0b44e85b3e36ec34a49dd1..254000bca2508d03722d19772680bf0e37047931 100644
--- a/build/config/win/BUILD.gn
+++ b/build/config/win/BUILD.gn
@@ -12,14 +12,16 @@ assert(is_win)
 # is applied to all targets. It is here to separate out the logic that is
 # Windows-only.
 config("compiler") {
-  asmflags = [
-    # When /safeseh is specified, the linker will only produce an image if it
-    # can also produce a table of the image's safe exception handlers. This
-    # table specifies for the operating system which exception handlers are
-    # valid for the image. Note that /SAFESEH isn't accepted on the command
-    # line, only /safeseh.
-    "/safeseh",
-  ]
+  if (current_cpu == "x86") {

[scottmg, 2015/12/01 21:44:44]

Are target_cpu and current_cpu the same here?

[Roland McGrath, 2015/12/01 21:49:23]

Not necessarily.  current_cpu is the proper one to test; it says what cpu this
config applies to.  target_cpu is what the overall build's so-called target is,
but that will not vary in different toolchain contexts as current_cpu does.  See
below in the same block where current_cpu is tested to choose -m32/-m64 options
for Clang.

[scottmg, 2015/12/01 21:49:31]

From `gn help target_cpu` and `gn help current_cpu`, I think target_cpu makes
more sense.

+    asmflags = [
+      # When /safeseh is specified, the linker will only produce an image if it
+      # can also produce a table of the image's safe exception handlers. This
+      # table specifies for the operating system which exception handlers are
+      # valid for the image. Note that /SAFESEH isn't accepted on the command
+      # line, only /safeseh. This is only accepted by ml.exe, not ml64.exe.
+      "/safeseh",
+    ]
+  }
 
   cflags = [
     "/Gy",  # Enable function-level linking.